The present application relates to tracked vehicles, and in particular, to track supports having changeable shapes and configurations.
Variable tracked vehicles can adjust track profiles in order to travel over barriers, staircases, and rough and soft terrains. Conventional variable tracked vehicles include two or more segments and dual tracks with changed positions between the two tracks, but the outlines of the tracks are not changeable. The large number of degrees of freedoms makes this type of variable tracked vehicles difficult to control and maneuver; their applications are limited.
U.S. patents and publications No. U.S. Pat. No. 7,690,738, US2011/0037311, and U.S. Pat. No. 7,600,592 respectively disclose track support mechanisms that can change track outlines in tracked vehicles.
U.S. Pat. No. 7,690,738 teaches a track support having a front and a rear rotatable arms. The track outer profile can be changed by adjusting the angular position of the two rotatable arms. When the two arms are rotated, the circumference of the track support, i.e. the length of the tightest possible belt wrapped around all the track engaging wheels of the track support are changeable. Thus the track belt must either be elastic, or can be loosened or tightened as the two arms rotate. This type of tack mechanism may therefore require a third mechanism for adjusting track tension, in addition to the two mechanisms for adjusting the arms. In the disclosed mechanism, the adjustable arms are implemented as hydraulic cylinders to maintain consistent tension in the tracks.
US2011/0037311 also teaches a track support having two arms with adjustable angles. The track outer profiles all have a trapezoidal shape, and a constant circumference.
U.S. Pat. No. 7,600,592 teaches a track support having a single rotatable arm. The track profile is changed by adjusting the angle of the rotatable arm. The circumference of the track support changes when the arm is rotated. This track support also needs to include a mechanism for adjusting the tension of the track at different configurations.
The above describe outline-variable track supports have limited configurations. Moreover, these outline-variable track supports have large turning radius and thus are harder to maneuver. The track supports also easily damage road surfaces.
There is therefore a need for a simple and a more effective variable track support without the above described drawbacks.